Biology SOL Unit 8.5 - Genetic Expression and Mutations

What is the role of tRNA in genetic expression?

• To carry amino acids

• To replicate DNA

• To splice RNA

• To form mRNA

Answer explanation

tRNA, or transfer RNA, plays a crucial role in genetic expression by carrying amino acids to the ribosome during protein synthesis. This process is essential for translating the genetic code into functional proteins.

Match the following definitions with the correct genetic expressions.4

• Mutation

• A change in the sequence of bases in DNA

• Translation

• mRNA directs protein synthesis with the assistance of tRNA, converting the RNA code into a protein sequence

• Transcription

• DNA is copied (transcribed) to mRNA, which carries the information needed for protein synthesis

• Replication

•  Creating an identical copy of a DNA molecule, essentially duplicating the genetic material before cell division

Answer explanation

Refer to Unit 8.5 Notes.

Tags

NGSS.HS-LS3-2

Match the following terms with their functions in the formation of nucleic acids.

• RNA Slicing

• Pre-messenger RNA is edited to produce desired mRNA structure

• RNA Polymerase

• Replicates DNA molecules to build a new strand of DNA

• DNA Polymerase

• Involved in the formation of pre-messenger RNA

Answer explanation

Refer to Unit 8.5 Notes.

What is the function of mRNA in genetic expression?

• To carry amino acids

• To direct protein synthesis

• To replicate DNA

• To splice RNA

Answer explanation

mRNA, or messenger RNA, serves to direct protein synthesis by carrying the genetic information from DNA to the ribosome, where proteins are assembled. This makes 'to direct protein synthesis' the correct function of mRNA.

Tags

NGSS.HS-LS1-1

What is the effect of a nonsense mutation on a polypeptide?

• It extends the polypeptide.

• It truncates the polypeptide.

• It has no effect.

• It duplicates the polypeptide.

Answer explanation

A nonsense mutation introduces a premature stop codon in the mRNA sequence, leading to a truncated polypeptide. This results in a shorter protein that may be nonfunctional, making 'It truncates the polypeptide' the correct choice.

Tags

NGSS.HS-LS1-1

NGSS.HS-LS3-2

What is the role of Watson-Crick base pairing in transcription?

• To replicate DNA

• To form pre-messenger RNA

• To splice RNA

• To synthesize proteins

Answer explanation

Watson-Crick base pairing is crucial in transcription as it allows the formation of pre-messenger RNA by pairing RNA nucleotides with the DNA template, ensuring accurate transcription of genetic information.

Match the following types of mutations with their descriptions.

• Missense Mutation

• A mutation that alters a single amino acid in the polypeptide chain

• Frameshift Mutation

• A mutation that results in a frameshift

• Silent Mutation

• A mutation that does not alter the amino acid sequence

• Inversion Mutation

• A mutation that involves chromosome inversion

Answer explanation

Refer to Unit 8.5 Notes.

Tags

NGSS.HS-LS3-2

Which disease is caused by a single base substitution mutation?

• Cystic fibrosis

• Sickle cell anemia

• Huntington's disease

• Down syndrome

Answer explanation

Sickle cell anemia is caused by a single base substitution mutation in the HBB gene, leading to the production of abnormal hemoglobin. This contrasts with cystic fibrosis, Huntington's disease, and Down syndrome, which have different genetic causes.

Tags

NGSS.HS-LS3-2

What is the result of a duplication mutation?

• A missing segment in the chromosome

• A longer chromosome with multiple copies of genes

• A flipped segment of DNA

• Two segments changing positions

Answer explanation

A duplication mutation results in a longer chromosome with multiple copies of genes, as segments of DNA are duplicated. This is distinct from other mutations like deletions or inversions.

Tags

NGSS.HS-LS3-2

What is translocation in chromosomal mutations?

• A segment of DNA is added to another chromosome

• A segment of DNA is lost

• A segment of DNA is repeated

• Two segments from different chromosomes change positions

Answer explanation

Translocation in chromosomal mutations occurs when two segments from different chromosomes change positions. This process can lead to genetic diversity but may also result in genetic disorders.